Components of the fertiliser nitrogen balance for wheat production on duplex soils

1992 ◽  
Vol 32 (7) ◽  
pp. 887 ◽  
Author(s):  
IR Fillery ◽  
KJ McInnes
Keyword(s):  
Growth Cycle ◽  
Review Literature ◽  
Rooting Depth ◽  
N Loss ◽  
Management Options ◽  
N Transformations ◽  
Time Of Application ◽  
Organic Matter Pool ◽  
Soil Organic Matter Pool ◽  
Western Australian

In this paper, we review literature on the fate of fertiliser nitrogen (N) applied to duplex soils in wheat-growing regions of southern Australia, and discuss the contribution of specific N transformations to N loss. Duplex soils are characterised by the presence of soil material, within the rooting depth of crops, that possess hydraulic conductivities that are lower than those of overlying material. Denitrification and the transport of nitrate below rooting depth of crops are thought to be the chief causes of loss of fertiliser N and to contribute to poor grain yields. Ammonia volatilisation could contribute also to N loss. The fate of fertiliser N commonly applied to wheat in southern Australia has largely been evaluated using budgeting procedures using l5N, a stable isotope of N. Results from studies in south-eastem Australia, using red-brown earths, indicate that between 10 and 40% of applied 15N can be lost irrespective of time of application to wheat. Denitrification is believed to be the chief cause of loss of l5N. Similar studies on yellow duplex soils in Western Australia have shown fertiliser N loss to range from 70% to no loss of the l5N applied. The exact cause of N loss in Western Australian studies is unclear. There was circumstantial evidence for ammonia loss from surface-applied urea, and evidence of leaching of nitrates from this and other ammoniumbased fertilisers. The role of denitrification has not been clarified in Western Australian studies. In the majority of studies, recovery of 15N in aboveground biomass exceeded 40% of that applied. In addition, between 17 and 48% of applied 15N, of which 10-15% may be in root material, has been recovered in the soil organic matter pool. The predominance of the denitrification process in south-eastern Australian soils, and the inability to improve the efficiency of utilisation of 15N by delaying the time of application to wheat underscores the importance of controlling the nitrification process using inhibitors. Management options for Western Australian soils are less clear. Some agronomic experiments have demonstrated the advantage of delaying the application of fertiliser N to wheat to improve the efficiency of its utilisation. There is also evidence which suggests that N should be applied early in the growth cycle to promote tiller development and thereby increase the potential for grain yield.

scholarly journals Quantifying nitrogen losses in oil palm plantations: models and challenges

2016 ◽  
Author(s):  
Lénaïc Pardon ◽  
Cécile Bessou ◽  
Nathalie Saint-Geours ◽  
Benoît Gabrielle ◽  
Ni’matul Khasanah ◽  
...  
Keyword(s):  
Oil Palm ◽  
Cropping Systems ◽  
N Uptake ◽  
Clay Content ◽  
Field Measurements ◽  
Growth Cycle ◽  
Rooting Depth ◽  
Perennial Crop ◽  
N Losses ◽  
Total N

Abstract. Oil palm is the most rapidly expanding tropical perennial crop. Its cultivation raises environmental concerns, notably related to the use of nitrogen (N) fertilisers and associated pollution and greenhouse gas emissions. While numerous and diverse models exist to estimate N losses from agriculture, very few are available for tropical perennial crops. Moreover, there has been no critical analysis of the performances of existing models in the specific context of tropical perennial cropping systems. We assessed the capacity of 11 models and 29 sub-models to estimate N losses in a typical oil palm plantation over a 25-year-growth cycle, through leaching and runoff, and emissions of NH3, N2, N2O, and NOx. Estimates of total N losses were very variable, ranging from 21 to 139 kg N ha−1 yr−1. On average, 31 % of the losses occurred during the first three years of the cycle. Leaching comprised about 80 % of the losses. Based on a comprehensive Morris sensitivity analysis, the most influential variables were soil clay content, rooting depth and oil palm N uptake. We also compared model estimates with published field measurements. Many challenges remain to model more accurately processes related to the peculiarities of perennial tropical crop systems such as oil palm.

Rate of recycling of sulfur from urine, feces and litter applied to the soil surface

Soil Research ◽  
1994 ◽  
Vol 32 (3) ◽  
pp. 543 ◽  
Author(s):  
GJ Blair ◽  
AR Till ◽  
C Boswell
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Surface ◽  
Plant Litter ◽  
Test Plant ◽  
Soil P ◽  
S Uptake ◽  
Organic Matter Pool ◽  
Preferential Uptake ◽  
Soil Organic Matter Pool

The recycling of S from plant litter, dung and urine is an important process for supplying S for pastures. A pot experiment was conducted where 35S-labelled litter (25% white clover/38% ryegrass/21% weed) and S-35-labelled urine and faeces collected from sheep fed the same herbage as was used as litter was surface applied to pots and the fate of the applied S was followed for 100 days with ryegrass as the test plant. In camp soil, 45% of the S applied in urine was taken up by ryegrass plants within 12 days of application. In non-camp soil, the uptake of urine-S was about 20% over the same period. Cumulative uptake of 35S from urine in camp soil was subsequently restricted, with a maximum of 60% eventually measured in plants after 100 days. Mean rates of release of S (0-37 days) from litter and faeces was respectively 16.2 and 4.5 mg g-1 day-1. The calculated half-times from S in the two materials were respectively 43 and 154 days under controlled environmental conditions with adequate moisture. Litter S followed organic matter (OM) decomposition, but faecal S release was initially more rapid than faecal OM decomposition. There was little S release from faeces after day 25. Rather, S was immobilized in faeces during the 25-100 day period. The decomposition of litter and faeces was divided into an initial rapid process during which soluble S and more labile S was released, followed by a slower process involving the release of S from tissues more resistant to mineralization. The uptake of 35S from labelled materials was initially more rapid than would be expected for total S released from the added litter and faeces and the 35Suptake effect was short-lived relative to the continued effect of added material on total S uptake. The preferential uptake of 35S from the surface-applied material appears to be due to limited root development at the early stages of the experiment. Movement of 35S into the soil organic matter pool was very rapid; 58.4% of urine S was in the soil organic matter fraction in the non-camp soil by day 6. The amount of applied S in the organic matter equilibrated at about day 75. The accumulation of applied S from the materials added was greater than that recorded in previously reported studies for inorganic sulfate (e.g. about 50%). Soil P and S status had little effect on rates of release of S. from the applied materials, however, the effect of the camp and non-camp soil on total S recycling was markedly different as a result of the different amounts of plant growth and thus S uptake in the two soils. The decomposition of litter indicated peak rates of S release at two specific times over the 100 days and indicated successional changes in micro-organism activity. With faeces, the experiment was not continued for sufficiently long to show micro-organism effects.

Flow systems, tree plantations, and salinisation in a Western Australian catchment

Soil Research ◽  
1997 ◽  
Vol 35 (5) ◽  
pp. 1213 ◽  
Author(s):  
W. J. Stolte ◽  
D. J. McFarlane ◽  
R. J. George
Keyword(s):  
Rooting Depth ◽  
Tree Plantations ◽  
Medium Term ◽  
Element Analysis ◽  
Saline Groundwater ◽  
Flow Mechanisms ◽  
Piezometric Heads ◽  
Vegetation Species ◽  
Western Australian

A lower hillslope in the Western Australian wheatbelt had become waterlogged and saline by 1981, when close-spaced rows of eucalypts were planted in blocks both in and adjacent to the discharge area and piezometers were established on the site. We analysed the trends in the piezometric heads and salinity concentrations over the period of record. We also modelled the hillslope profile using finite element analysis to determine the water flow mechanisms and to see how a change in vegetation in the upland area would affect the waterlogging and salinity. Piezometric levels under the trees decreased for the first 5 years after planting and then stabilised until 1991 when they started gradually decreasing again. The non-treed area between the plantation blocks remained unaffected until about 1991, when the levels there also started to decrease quite significantly, probably because of the trees. The trees therefore appear to have been effective and beneficial in the short to medium term. However, the salinity of the groundwater under the trees has increased significantly in the last 5 years, particularly where the tree density is highest. The continued flow of saline groundwater to the trees is believed to be increasing the salinity. It could not be expected that plantations of this type will maintain health and be able to control the excess water in such an hydrologic setting in the long term. Tree plantations on discharge areas are a short to medium term management strategy, not a solution, and the only way to control salinity in the long term is to plant vegetation species in the recharge areas that use all of the water that falls there. Modelling showed that only a small surplus of water over winter, in the order of 50 mm/year, caused the increased recharge and consequent salinisation. The modelling results also show that the surplus could be managed with an effective vegetation species (e.g. lucerne) with a rooting depth of about 1·5 m that would be able to transpire at least until early to mid summer.

The current and future projected distribution of Solanum hoplopetalum (Solanaceae): an indigenous weed of the south-western Australian grain belt

2012 ◽  
Vol 60 (2) ◽  
pp. 128 ◽  
Author(s):  
Pippa J. Michael ◽  
Paul B. Yeoh ◽  
John K. Scott
Keyword(s):  
Climate Change ◽  
Current Distribution ◽  
South Australia ◽  
Climate Change Scenarios ◽  
Management Options ◽  
South Wales ◽  
Major Factors ◽  
Lower South ◽  
Significant Match ◽  
Western Australian

The factors determining the distribution of the Western Australian endemic Solanum hoplopetalum Bitter & Summerh. (Solanaceae) were assessed because it was identified as a potential weed risk to Australian cropping regions, including under climate change scenarios. Incubation at constant temperatures determined daily plant growth rates and plants required 1380 degree-days above a threshold of 12.4°C to complete growth to flowering. From this and published information on the plant’s biology, we developed a mechanistic niche model using CLIMEX. The model projection for current climates produced a highly significant match to known distribution records. Spatially, the lower south-west and areas eastwards to South Australia, western New South Wales and southern parts of the Northern Territory were climatically suitable for growth of S. hoplopetalum. However, by 2070 the area under risk decreases, with the projected distribution under climate change contracting southwards. We hypothesise that climatic extremes and edaphic factors, possibly high soil pH, may be major factors determining the current distribution of S. hoplopetalum. Containment on the southern edge of the current distribution, interstate quarantine and local eradication in new areas of invasion are recommended as management options to combat the potential for this native weed to spread.

scholarly journals Impact of dust accumulation on yield and yield components of soybean

2020 ◽  
Vol 116 (1) ◽  
pp. 145
Author(s):  
Sharife HABIBPOUR ◽  
Majid AMINI DAHAGHI ◽  
Mohammad-Eghbal GHOBADI ◽  
Alaeddin KORDENAEEJ
Keyword(s):  
Stomatal Conductance ◽  
Yield Components ◽  
Block Design ◽  
Seed Mass ◽  
Growth Cycle ◽  
Yield Component ◽  
Seed Formation ◽  
Time Of Application ◽  
Randomized Complete Block Design ◽  
Beginning Of Flowering

<p>This study aimed to characterize if dust sprayed on soybean foliage impacts its yield and yield component characteristics. In 2017 and 2018, soybean [<em>Glycine max</em> (L.) Merr.] was planted using a factorial randomized complete block design with three replicates. Plants were sprayed with a 20 g m<sup>-2</sup> of dust at four stages of the growth cycle, including third-node, the beginning of flowering, the beginning of podding, and the beginning of seed formation. Dust spraying was then continued twice weekly until the late full seed stage. Plant measurements included yield, yield components, stomatal conductance, peroxidase, and superoxide dismutase antioxidant enzymes activities. Results showed that depending on the time of application, the dust coverage created a range of yield loss in soybeans, most likely due to a reduction in stomatal conductance, grains plant<sup>-1</sup> and 100-seed mass. Therefore, soybean fields that are regularly exposed to dust might be subjected to reduced yield.</p>

scholarly journals Sustainable water use for rice agro-ecosystems in northern Italy

2020 ◽  
Author(s):  
Arianna Facchi ◽  
Alice Mayer ◽  
Enrico Chiaradia ◽  
Andrea Ricciardelli ◽  
Michele Rienzner ◽  
...  
Keyword(s):  
Water Productivity ◽  
Irrigation Management ◽  
Soil Survey ◽  
Irrigation District ◽  
Water Inflow ◽  
Rooting Depth ◽  
Rice Grain ◽  
Water Balance Components ◽  
Management Options ◽  
Continuous Flooding

&lt;p&gt;In the Mediterranean basin, rice is cultivated over an area of 1,300,000 hectares. The most important rice-producing countries are Italy and Spain in Europe (72% of the EU production; 345,000 ha), and Egypt and Turkey among the extra-EU countries (almost totality of the production; 789,000 ha). Traditionally, rice is grown under continuous flooding; thus, it requires much more irrigation than non-ponded crops. The MEDWATERICE project (PRIMA-Section 2-2018; https://www.medwaterice.org/) aims at exploring sustainability of innovative rice irrigation management solutions, in order to reduce rice water consumption and environmental impacts, and to extend rice cultivation outside of traditional paddy areas to meet the escalating demand. Within the MEDWATERICE project, irrigation management options to address the main site-specific problems are being tested for each rice areas involved in the project (IT, ES, PT, EG, TR). Case studies are being conducted in pilot farms, with the involvement of Stake-Holder Panels (SHPs) in each country. Data collected at the farm level will be extrapolated to the irrigation district level, to support water management decisions and policies. Moreover, indicators for quantitative assessment of environmental, economic and social sustainability of the irrigation options will be defined.&lt;/p&gt;&lt;p&gt;This work illustrates the first year of results for the Italian Case Study (Lomellina area, Pavia) at the pilot farm scale. This area is characterized by a growing water scarcity in drought years in many districts. Within the farm managed by the National Rice Research Center (CRR), in the agricultural season 2019 the experimentation was conducted in six plots of about 20 m x 80 m each, with two replicates for each of the following water regimes: i) water-seeded rice with continuous flooding (WFL), ii) dry-seeded rice with continuous flooding from the 3-4 leaf stage (DFL), and iii) water seeded-rice with alternate wetting and drying from fertilization at the tillering stage (AWD). One out of the two replicates of each treatment was instrumented with: water inflow and outflow meters, set of piezometers, set of tensiometers and water tubes for the irrigation management in the AWD plots. A soil survey was conducted before the agricultural season (EMI sensor and physico-chemical analysis of soil samples). Periodic measurements of crop biometric parameters (LAI, crop height, crop rooting depth) were performed. Moreover, nutrients (TN, NO&lt;sub&gt;3&lt;/sub&gt;, PO&lt;sub&gt;4&lt;/sub&gt;, K) and two widely used pesticides (Sirtaki &amp;#8211; a.i. Clomazone; Tripion E &amp;#8211; a.i. MCPA) were measured in irrigation water (inflow and outflow), groundwater, and porous cups installed at two soil depths (20 and 70 cm, above and below the plough pan). Finally, rice grain yields and quality (As and Cd in the grain) were determined. First results in terms of cumulative water balance components (rainfall, irrigation inflow and outflow, difference in soil and ponding water storage, evapotranspiration, net percolation), water application efficiency (evapotranspiration over net water input), and water productivity (grain production over net water input), will be presented and discussed. Results of a 1D Richard-equation-based numerical simulation model applied to generalize results obtained under the different irrigation regimes will be moreover illustrated.&lt;/p&gt;

Reducing denitrification loss with nitrification inhibitors following presowing applications of urea to a cottonfield

1994 ◽  
Vol 34 (1) ◽  
pp. 75 ◽  
Author(s):  
DL Chen ◽  
JR Freney ◽  
AR Mosier ◽  
PM Chalk
Keyword(s):  
Soil Loss ◽  
New South ◽  
New South Wales ◽  
Calcium Carbide ◽  
Nitrification Inhibitors ◽  
N Loss ◽  
Mineral N ◽  
N Transformations ◽  
South Wales ◽  
Denitrification Loss

The effects of the nitrification inhibitors nitrapyrin, acetylene (provided by wax-coated calcium carbide), and phenylacetylene on nitrogen (N) transformations and denitrification losses following presowing applications of urea were determined in a cottonfield in the Namoi Valley of New South Wales. The study used 0.05-m-diameter microplots to follow the changes in mineral N, and 0.15-m-diameter microplots fertilised with 15N-labelled urea (6 g N/ m2; 5 atom % 15N) to assess losses of applied N. When urea was applied in February (34 weeks before sowing), 84% of applied N was lost from the soil. Loss of applied N was reduced by addition of nitrapyrin and phenylacetylene, to 53 and 57%, respectively. In the absence of nitrification inhibitors, less N was lost (72% of that applied) from an application in May than from the February application. Addition of acetylene, phenylacetylene, and nitrapyrin reduced losses over the 24 weeks to sowing to 57, 52, and 48%, respectively. These experiments show that N loss from presowing applications of urea can be significantly reduced by the use of nitrification inhibitors, but that the losses of N are still substantial.

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